Quests Missions leveling before and after Searing

I just picked up the game on Saturuday.

Currently I am a level 6 Elementalist/Ranger Pre searing Ascalon area. I have just been doing all the quests that NPC's give me. Im curious, that if I go and talk to Sir Tydus, which is when you go to battle or somthing right?, Then the searing occurs, are all the quests available to you before the searing gone from NPC's available to you after the Searing as well? Would it be wise for me to try do all the NPC quests before hand? I know I am kind of taking the approach of trying to do everything in the game.

I have been exploreing and such going in to the mountains, catacombs and stuff like that.

I just havn't gone and talked to Sir Tydus yet, and have been doing all these NPC quests. I didnt really even realize that there are Missions.

Which gets me to my second question where do you get missions from?

Also are there things I should do/aquire before I go and talk to Sir Tydus?

Thanks,

Lib

http://www.guildwarsguru.com/content...-10-id1195.php

http://www.guildwarsguru.com/content...lon-id1264.php

the presear guide especially

get 2nd profession and skills for it

sir tydus is still alive post sear

Where do missions come from?

Mission and quests are different correct?

Also how far away can I venture post sear? It seems like I can go quite a ways...